In general, a conductive circuit pattern is formed on a substrate through an expose process or an etching process using a photomask. However, there is a limit in forming a complicated and micro circuit pattern by using a photomask.
Accordingly, in order to conveniently form a micro circuit pattern, it has been suggested that a paste containing Au or Ag is applied on a substrate, and then is cured to form a circuit pattern. The related arts are Korean Patent Application Publication No. 2008-0026165 entitled “A silver paste composition, a method for forming a conductive pattern using the same and a conductive pattern thereof” and Korean Patent Application Publication No. 2010-0046285 entitled “Silver microparticle-containing composition, a method for forming the same, a method for forming a silver microparticle, and a paste having silver microparticle.”
However, precious metals, such as Au or Ag, are expensive. Accordingly, the use of a paste that contains precious metals causes a problem of incurring excessive costs for forming a circuit pattern.